2 allyl-3-chloro-2-cyclohexen-1-ones and their preparation

ABSTRACT

2-Allyl-3-chloro-2-cyclohexen-1-ones and alkyl (C1-C3) substituted derivatives are prepared by allylation of dihydroresorcinol, followed by chlorination with phosphorus oxychloride. They can be reacted with sodium hydrosulfide to form 2-alkyl-4-oxo-2,3,4,5,6,7-hexahydrobenzo(b) thiophenes and alkyl (C1-C3) substituted derivatives, which are dehydrogenated to produce alkyl substituted 4-hydroxybenzo(b) thiopenes and 2,3dihydro derivatives thereof and converted to carbamate insecticides.

[ Dec. 3, 1974 ALLYL-3-CHLORO-Z CYCLOHEXEN- l-ONES AND THEllR PREPARATION [75] Inventor: Jerry G. Strong, Fanwood, NJ.

[73] Assignee: Mobil Oil Corporation, New York,

[22] Filed: Jan. 18, 1973 [21] Appl. No.: 324,632

Related U.S. Application Data [63] Continuation-impart of Ser. No. 11,898, Feb. 16,

1970, abandoned.

[52] US. Cl. 260/586 R, 260/587 [51] int. Cl. C07c 49/48 [58 Field of Search 260/586 R, 587

[56] References Cited UNITED STATES PATENTS 2,871,267 1/1959 Petracek et a1 260/586 R 2,927,134 3/1960 Normant et a1 260/586 R 3,114,772 12/1963 Lorette et a1. 260/586 R 3,331,856 7/1967 Los 260/586 R X 3,431,305 3/1969 Thompson et a1. 260/586 R Primary ExaminerBernard Helfin Assistant Examiner-Norman P. Morgenstern Attorney, Agent, or Firm-Andrew L. Gaboriault; Hastings S. Trigg [5 7] ABSTRACT 6 Claims, N0 Drawings A 1 2 ALLYL-3-CIIL0R0-24CYCLOHEXEN-1-0NES AND THEIR PREPARATION CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of copending application Ser. No. 11,898, filed Feb. 16, 1970 now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is concerned with novel alkyl substituted 2-a1lyl-3-chloro-2-cyclohexen-l-ones and their preparation.

2. Description of the Prior Art Insofar as is nowknown the compounds of this invention have not been described in the prior art.

SUMMARY OF THE INVENTION This invention provides 2-allyl-3-chloro-2- cyclohexen-l-ones having the formula:

wherein R, R, R", R', R"" and R are hydrogen or C1-C3 alkyl.

It also provides a method for preparing 2-allyl-3- chloro-2-cyclohexen-l-ones that comprises reacting dihydroresorcinol with an allyl compound having the formula:

' IV IIFEIQH'T R RI!!! wherein R, R, R, R, and R"" are hydrogen or C -C alkyl and X is Br or CI to form a 2-allyl 1,3-

cyclohexanedione in alkaline medium and reacting said 2-allyl-1,3-cyclohexanedione with phosphorus oxychloride.

DESCRIPTION OF SPECIFIC EMBODIMENTS The compounds of this invention are 2-allyl-3- chloro-Z-cyclohexen-l-one and derivatives thereof having alkyl (C -C substituents on the allyl side chain and'thecyclohexenonering. For simplicity and uniformity in nomenclature, the derivatives will be named on the basis ofth'e allyl side chain. Typical compounds are:

. 2-allyl-3-chloro-2-cyclohexen-l-one;

2-methallyl-3-chloro-2-cyclohexen- 1 -one;

2-(Z-ethylallyl)-3-chloro-2-cyclohexen-l-one;

2-(2-propylallyl)-3-chloro-2-cycloh'exen-1-one; 2-(3-methylallyl)-3-chloro-2-cyclohex'en-1-one; 2-(2,3,3-trimethylallyl) 3-chloro-2-cyclohexenl-one; i

2-( 2,3-dimethylallyl )-3-chloro-2-cyclohexen- 1 -one; 2-(3,3-dimethylallyl)-3-chloro-2-cyclohexen-l-one; 2-(3- ethylallyl)-3-chloro-2-cyclohexen-l-one;

wherein R, R, R", R', and R"" are hydrogen or C -C alkyl and X is Br or Cl. Non-limiting examples are allyl bromide; allyl chloride; methallyl bromide; methallyl chloride; 2-ethylallyl bromide; 2-propylallyl chloride; B-methylallyl bromide; 2,3,3-trimethylallyl chloride; 2,3-dimethylallyl bromide; 3,3-dimethylallyl chloride; 3-ethylallyl bromide; 2-methyl-3-ethylallyl chloride; l-methylallyl bromide; ll-methyl-l-ethylallyl chloride; 1,2-dimethylallyl bromide; l-ethylallyl chloride; l,l -diethylallyl bromide; 1,1-dimethylallyl chloride; and l-propylallyl bromide.

The allylation of dihydroresorcinol is carried out by reacting dihydroresorcinol with the allyl bromide or chloride reactant in an alkaline (NaOI-l, KOH) medium. The reaction takes place at room temperature. Typical procedures are described in Chem. Ber., 85, 1061-7 (1952) (CA. 47zl2228i) and Chem. Ber., 94, 2394 (1961) (CA. 56:1361c). The following examples illustrate the techniques involved.

EXAMPLE 1 Allyl bromide (59.5 g., 0.49 mole) was added gradually to a cooled solution of 64.8 g. (0.58 mole) 1,3- cyclohexanedione and 32.4 g. (0.58 mole) potassium hydroxide in cc. water, using rapid stirring. When clumps of needlelike crystals started to form, addition of allyl bromide was stopped and 20 per cent aqueous potassium hydroxide was added until solution was ef-,.

fected. Addition of allyl'bromide was then completed in about ten hours. The reaction mixture was added to 200 cc. of normal sodium hydroxide. The solution was extracted with 3 portions of petroleum ether. The remaining aqueous solution was icc cooled and'adjusted to, pH 5 with concentrated hydrochloric acid. Crystals were filtered off and'water washed. Recrystallization from methanol/water (1:3) gave fine needles of 2-allyl- 1,3-cyclohexanedione melting at 128C.

' EXAMPLE 2 A 91 g. (1.0 mole) portionofmethallyl chloride was added to a solution of 123 g. (1.1 mole) of.1,3- cyclohexanedione and 62 g. (1.1 mole) of potassium rated crystals were collected, washed with water, and dried to afford 91 g. of 2-methallyl-l,3-

cyclohexanedione melting at ll3l14C.

The 2-allyl-3-chloro-2-cyclohexen-l-one or an alkyl derivative is prepared by the reaction of phosphorus oxychloride with the 2-allyl-l ,3-cyclohexanedione. The techniques involved are demonstrated in the following examples:

EXAMPLE 3 A 91 g. (0.6 mole) portion of phosphorus oxychloride was added dropwise to a solution of 46 g. (0.3 mole) of 2-allyl-l,3-cyclohexanedione and 52 g. of N,N-dimethylaniline in 300 ml. of chloroform so as to control the temperature near 40C. Following 4 hours of stirring at ambient temperature, the reaction solution was gently concentrated and cautiously poured over cracked ice so as to control the temperature near 40C. The resulting mixture was thoroughly extracted with ether, and the ethereal solution was washed with 5 per cent sodium hydroxide and with brine, dried and concentrated. The clear liquid obtained weighed 40 g. and was distilled through ashort path apparatus to afford 34 g. (0.2 mole; 70 percent) of 2-allyl-3-chloro-2- EXAMPLE 4 A 121 g. (0.8 mole) portion of phosphorus oxychlo-' ride was allowed to react with 66 g. (0.4 mole) of 2- methallyl-l,3-cyclohexanedione and 70 g. of N,N- dimethylaniline inr400 ml. of chloroform using the same procedure as described in Example 3. Obtained by the same isolation procedure was 45 g. (0.25 mole; 62 percent) of 2 -methallyl-3-chloro-2-cyclohexenl-onez- BP 64-70 (0.15 mm.), Mfilm) 5.9541

The compounds of this invention can be reacted with sodium hydrosulfide to form 2-alkyl-4-oxo-2,3,4,5,6,7-

hexahydrobenzo [b] thiophenes and C -C alkyl substituted derivatives, as described in copending application Ser. No. 11,896, filed Feb. '16, 1970 now U.S..Pat. No. 3,743,655. The 2-alkyl-4-oxo-2,3,4,5,6,7 hexahydrobenzo [b] thiophenes and C, C;, alkyl substituted derivatives are dehydrogenated to produce 4- hydroxybenzo [b] thiophenes and 2,3-dihydro derivatives thereof. The dehydrogenation can be carried out in the vapor phase, in the absence ofadded hydrogen,

using water .in thefeed and a metal oxide catalyst of Groups Vl Band Vlll (iron sub-group) metals, as defined in US. Pat. No. 3,345,382.-The dehydrogenation can also be carried out inthe liquid phase by applying hydroxide in 250 ml. water using rapid stirring. The rethe procedures of US. Pat. No. 3,317,552 i.e., by heating a solution of elemental sulfur and the 0x0- compound in a solvent for both the sulfur and the 0x0- compound. The resulting 4-hydroxy compound can be converted to carbamate insecticides. Typically the carbamates are formed by reacting the hydroxy compound with an isocyanate, such as alkylisocyanate, or with I What is claimed is: g r

l. 2-allyl-3-chloro-2-cyclohexen-l-ones having the formula:

2. The compound of claim R' and R" are hydrogen.

3. The compound of claim 1, wherein R" is methyl and R, R5, R, R', and R"" are hydrogen.

4. A method for preparing 2-allyl-3-chloro-2- cyclohexen-l-ones that comprises reacting dihydroresorcinol with an allyl compound having the formula:

1, wherein R, R5, R, R",

wherein R, R, R", R and R"" are hydrogen or C,C alkyl and X is Br or Cl in alkaline medium-to form a 2-allyl-l,3-cyclohexanedione, separating said 2-allyl-l ,3-cyclohexanedione and reacting it with phosphorus oxychloride by gradually adding an N,N- dimethylaniline-chloroform solvent solution of phosphorus oxychloride to said 2-allyl-l ,3- cyclo'hexanedione at a temperature of about 40C, concentrating the reaction mixture and extracting a 2-allyl- 3-chloro-2-cyclohexen-l-one with ether.

5. The method of claim 4, wherein R, R, R", R, and R"" are hydrogen and X is Br.

6. The method of claim 4, wherein R" is methyl, R,

R, R', and R"" are hydrogen and X is Cl. 

1. 2-ALLYL-3-CHLORO-2-CYCLOHEXEN-1-ONES HAVING THE FORMULA:
 2. The compound of claim 1, wherein R, R5, R'', R'''', R'''''' and R'''''''' are hydrogen.
 3. The compound of claim 1, wherein R'''' is methyl and R, R5, R'', R'''''', and R'''''''' are hydrogen.
 4. A method for preparing 2-allyl-3-chloro-2-cyclohexen-1-ones that comprises reacting dihydroresorcinol with an allyl compound having the formuLa:
 5. The method of claim 4, wherein R, R'', R'''', R'''''', and R'''''''' are hydrogen and X is Br.
 6. The method of claim 4, wherein R'''' is methyl, R, R'', R'''''', and R'''''''' are hydrogen and X is Cl. 